Create a USB and the LE install files are in the boot partition of the USB, or grab the update .tar file and unpack it, they're in the target folder. I'm not aware of anyone writing up exact instructions for this scenario, but "install grub linux" returns 500k+ results in Google and the rest requires "gparted" and some copy/paste in Ubuntu so I guess there's some instructions around. Just have a go, you can't break anything..
It seems ridiculous to have to do all that. There are instructions how to do it
Installation - LibreELEC
The main danger AFAICS is the install from USB doesn't give you the option to run it from memory as most sensible Linux installs do, people like to try things rather than committing irrevocably to disk from the start!
The options are default: automatic boot, tab gives the 'option' of 'installer live' . Maybe this is run from memory? Who knows. After that you get a choice of Quick Install, Repair/Upgrade or Logfile.
And (apparently) since version 7, there is no option to install the 32bit version.
PS to the OP, after writing to the USB stick you should be able to see files/directories in it, if you can't then it hasn't copied them correctly